异构网中下行信号干扰协调方法的研究

发布时间：2018-03-31 11:57

本文选题：全球移动通信系统　切入点：异构网　出处：《中国科学技术大学》2014年硕士论文

【摘要】：随着移动互联网和智能终端的发展以及UMTS系统的演进,高速下行链路分组接入(HSDPA)技术已经成为增强UMTS系统链路性能的重要手段。异构网技术由于引入了低功率节点,如微微(Pico)基站、家庭(Femto)基站和中继(Relay)基站等,达到降低宏基站负载、提升网络容量和增强网络覆盖的目的。鉴于此,UMTS HSDPA系统中引入异构网技术来提高系统性能也是很有实际意义的。本论文重点研究了在UMTS系统中引入异构网技术后的下行信号干扰协调问题,主要是Macro-Pico异构网中Pico基站边缘下行高干扰用户的干扰协调问题。论文首先对异构网技术进行了介绍,重点对异构网中的干扰类型进行了分类和总结,对基于LTE架构和UMTS系统的异构网的区别进行了分析,并介绍了异构网中的低功率节点覆盖增强技术(RE)以及基于时域、频域、空域和码域的下行干扰协调技术,重点对几乎空白子帧方案(ABS方案)进行了综述。其次,论文对传统的ABS干扰协调方案中ABS子帧比例的确定方法进行了介绍,提出了一种改进的ABS子帧比例确定方法,并进行了仿真分析。之后论文对ABS方案和多流方案的适用情况进行了分析,提出了一种ABS方案和多流方案相结合的干扰协调方案,该方案将Pico基站边缘高干扰用户分类为ABS用户和多流用户,对不同的用户采用不同的干扰协调方案。仿真结果表明了该方案在某些场景下比单独使用ABS方案有优势。针对传统的ABS方案的缺点,论文提出了一种下行的空域干扰协调方案,即Macro基站在ABS子帧上并不是完全不发送数据,而是采用基于有限码本的预编码进行数据传输,在减小Macro基站对Pico基站边缘用户的下行干扰的同时,使Macro基站用户性能不受太大影响。我们对不采用干扰协调的情况(Norm)、采用ABS方案的情况以及采用所提方案(CS)的情况进行了仿真比对,结果表明,所提的方案在用户平均吞吐率的性能上好于ABS方案,更接近于Norm方案；在最差5%用户吞吐率性能上,所提方案优于Norm方案,更接近于ABS方案,取得了较好的性能折中。这说明所提干扰协调方案能够在让Pico基站边缘高干扰用户性能提高的前提下,保证系统吞吐量。
[Abstract]:With the development of mobile Internet and intelligent terminals and the evolution of UMTS system, high-speed downlink packet access (HSDPA) technology has become an important means to enhance the link performance of UMTS systems. Such as pico base station, home Femto base station and relay Relay base station, so as to reduce the load of Acer station. The purpose of enhancing network capacity and network coverage is to increase network capacity. In view of the fact that heterogeneous network technology is introduced into UMTS HSDPA system to improve system performance, this paper focuses on the introduction of heterogeneous network technology in UMTS system. Downlink signal interference coordination problem, The main problem is the interference coordination problem of Pico base station edge downlink high interference users in Macro-Pico heterogeneous network. In this paper, the technology of heterogeneous network is introduced, and the types of interference in heterogeneous network are classified and summarized. The differences between heterogeneous network based on LTE architecture and UMTS system are analyzed. The low power node coverage enhancement technique in heterogeneous networks and the downlink interference coordination techniques based on time domain, frequency domain, spatial domain and code domain are also introduced, with emphasis on the almost blank sub-frame scheme (ABS scheme). Secondly, the paper introduces the method of determining the proportion of ABS subframes in the traditional ABS interference coordination scheme, and proposes an improved method for determining the ratio of ABS subframes. Then the application of ABS scheme and multi-stream scheme is analyzed, and a kind of interference coordination scheme combining ABS scheme and multi-stream scheme is proposed. The scheme classifies the Pico base station edge high-interference users into ABS users and multi-stream users, and adopts different interference coordination schemes for different users. The simulation results show that this scheme has advantages over using ABS alone in some scenarios. Aiming at the shortcomings of the traditional ABS scheme, this paper proposes a downlink spatial interference coordination scheme, that is, the Macro base station does not send data completely on the ABS subframe, but uses the precoding based on the finite codebook for data transmission. While reducing the downlink interference of the Macro base station to the edge users of the Pico base station, The user performance of Macro base station is not greatly affected. The simulation results show that the ABS scheme and the proposed scheme are compared with each other in the case of no interference coordination. The performance of the proposed scheme is better than that of the ABS scheme and is closer to that of the Norm scheme, and the proposed scheme is better than the Norm scheme and closer to the ABS scheme in the worst 5% user throughput performance. A good performance compromise is achieved, which shows that the proposed interference coordination scheme can ensure the system throughput while improving the performance of users with high interference at the edge of the Pico base station.
【学位授予单位】：中国科学技术大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN972

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